平邑甜茶根系及mhp-miR164a对根区压力的响应

Response of root system and mhp-miR164a of Malus hupehensis var.pingyiensis to root zone pressure

本研究以平邑甜茶(Malus hupehensis var.pingyiensis)幼苗和转mhp-miR164a拟南芥为试材,在砂培条件下,通过根区加压,分析根系变化和mhp-miR164a的作用。结果表明,根区加压显著改变平邑甜茶和拟南芥根系形态结构。根区加压下调平邑甜茶根系mhp-miR164a的表达,压力54~90 kPa显著抑制平邑甜茶主根生长,促进其侧根形成。未加压条件下,过表达mhp-miR164a拟南芥侧根数显著低于野生型。对根区施加54 kPa压力后,与对照相比,野生型拟南芥的侧根数显著增加,过表达mhp-miR164a拟南芥的主根长和侧根数均显著降低,且显著低于加压下野生型的主根长和侧根数。过表达mhp-miR164a拟南芥对高硬度培养基穿透能力显著降低。这些结果表明mhp-miR164a负调控平邑甜茶侧根发生及根系抵抗根区压力的能力。

In this study,Malus hupehensis var.pingyiensis seedlings and transgenic mhp-mi R164a Arabidopsis thaliana were used as materials,the changes of root system and the role of mhp-miR164a were analyzed under the sand culture conditions.The results showed that root zone pressure significantly changed root morphology and structure of M.hupehensis var.pingyiensis and A.thaliana.Root zone pressure down-regulated the expression of mhp-mi R164a in the root system of M.hupehensis var.pingyiensis.The pressure of 54–90 kPa significantly inhibited the main roots growth and promoted the lateral roots formation.Under non-pressurized condition,the number of lateral roots of A.thaliana overexpressing mhp-miR164a was significantly lower than that of wild type.Under the pressure of 54 kPa,the number of lateral roots of wild type A.thaliana increased significantly,while the axial root length and lateral root number of A.thaliana overexpressing mhp-mi R164a were significantly lower than those of control,and significantly lower than those of wild type under pressure.The penetration ability of A.thaliana to high hardness medium was significantly decreased by overexpressing mhp-miR164a.These results suggest that mhp-miR164a negatively regulates lateral rooting and root resistance to root zone pressure in M.hupehensis var.pingyiensis.